29 U.S. Code § 1396 - Special rules for plans under section 404(c) of title 26

(a) Amount of withdrawal liability; determinative factorsIn the case of a plan described in subsection (b)—

(1) if an employer withdraws prior to a termination described in section 1341a(a)(2) of this title, the amount of withdrawal liability to be paid in any year by such employer shall be an amount equal to the greater of—

the number of contribution base units for which the employer would have been required to make contributions for the prior plan year if the employer had not withdrawn, multiplied by

(ii)

the contribution rate for the plan year which would be required to meet the amortization schedules contained in section 1423(d)(3)(B)(ii) [1] of this title (determined without regard to any limitation on such rate otherwise provided by this subchapter)

except that an employer shall not be required to pay an amount in excess of the withdrawal liability computed with interest; and

(2) the withdrawal liability of an employer who withdraws after December 31, 1983, as a result of a termination described in section 1341a(a)(2) of this title which is agreed to by the labor organization that appoints the employee representative on the joint board of trustees which sponsors the plan, shall be determined under subsection (c) if—

(A)

as a result of prior employer withdrawals in any plan year commencing after January 1, 1980, the number of contribution base units is reduced to less than 67 percent of the average number of such units for the calendar years 1974 through 1979; and

(B)

at least 50 percent of the withdrawal liability attributable to the first 33 percent decline described in subparagraph (A) has been determined by the plan sponsor to be uncollectible within the meaning of regulations of the corporation of general applicability; and

(C)

the rate of employer contributions under the plan for each plan year following the first plan year beginning after September 26, 1980 and preceding the termination date equals or exceeds the rate described in section 1423(d)(3) 1 of this title.

For purposes of paragraph (1), the term “a year of signatory service” means a year during any portion of which a participant was employed for an employer who was obligated to contribute in that year, or who was subsequently obligated to contribute.